Messages in this thread | | | From | Rusty Russell <> | Subject | Re: [PATCH] [RFC] remove (more or less) unnecessary cacheline_aligned from module_ref | Date | Mon, 12 Jan 2009 21:38:48 +1030 |
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On Monday 12 January 2009 13:48:41 Kyle McMartin wrote: > On x86_64 systems with CONFIG_MAXSMP set, NR_CPUS is exploded to 4096 > cpus. This cacheline_aligned attribute on the local_t in module_ref > results in struct module bloating to over 512KB in size on x86_64, which > tends to, er, add up. This results in insane disk usage on distro > kernel configs (1GB+ on Fedora.) > > Killing cacheline_aligned reduces the size of struct module to somewhat > more sane levels. > > Signed-off-by: Kyle McMartin <kyle@redhat.com>
Yep, I've applied this.
> I'll followup with a patch to make mod->ref dynamically allocated, but > that needs a bit more thinking because module_unload_init currently > doesn't have a failure path.
Thanks, that'd be good. And it'll be even nicer when the new per-cpu allocator goes in.
Thanks, Rusty.
It really needs the per-cpu alloc patches which are pending to make it
> > Of course, reducing NR_CPUS to something sane was an easy way to patch > over the problem. > > diff --git a/include/linux/module.h b/include/linux/module.h > index 4f7ea12..32b0bda 100644 > --- a/include/linux/module.h > +++ b/include/linux/module.h > @@ -222,7 +222,7 @@ void *__symbol_get_gpl(const char *symbol); > struct module_ref > { > local_t count; > -} ____cacheline_aligned; > +}; > > enum module_state > { >
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